Automatic firearm



fr. F.l HoRAN AUTOMATIC FIREARM ug. 29, l 944.

3 Sheets-Sheet 1 Filed July 30, 1940 T. F. HORAN AUTOMATIC FIREARM 5 Sheets-She'et 2 Filed July 50, 1940 Patented ug. 29, 1944 Ap'romrio FIREARM Application July 30, 1940, Serial No. 348,429

5 Claims.

This invention relates to firearms, and more particularly to a firearm of the automatic type wherein the breech bolt is moved rearwardly in the receiver by the firing reaction, and returned to a forward position by spring action, the movement of the bolt serving to actuate mechanism to throw a fresh cartridge from the magazine of the gun into the chamber,'so that at the end of the cycle of operations resultant' upon the firing of the gun a fresh cartridge isin the chamber and the gun ready for a subsequent firing.

Some difficulty has at times been experienced with guns of this type in that, whenthe bolt has been blown rearwardly by the firing reaction and is returned by the kspring provided for thatpurpose, the actionA takesplace so quickly that suicient time has not, been allowed to permit the fresh cartridge to, be moved to a position. Where it will be thrown into the chamber by the return of the bolt. This will cause the gun to jam, and results in considerable inconvenience to the operator.

It is contemplated by the present invention temporarily to retard or delay the return of the bolt to breech-closing position, so that this return will not take place until the cartridge lifter has had suficient time to operate and lift the fresh cartridge into a position in front of the chamber. In the embodiments of the inventionI shown, this retardation of the return of the bolt is effected Aby a detent which serves to delay the return of the bolt, and in some forms of the invention this detent is connected to the trigger, whereby when the trigger is pulled the detent will be permitted to move to a position to engage a part of the bolt when the latter is moved rearwardly, and this detent will hold the bolt in a rearward position until the trigger has been released. Uponrelease ofV the trigger the latter will be moved forwardly by the trigger spring,` and the forward motion of the trigger will move the detcnt to disengaging 'position Vand permit the return of the bolt to breech-closing position by its spring. As in firearms of this type it is necessary for the user of the gun to release his nger pressure on the trigger between firing operations, it will be apparent that this will not result in any inconvenience to the user, nor will .it interfere with the rapidity -ofthe operationy of the gun, in that immediately upon release of ythe trigger the bolt will be returnedto `breech-closing position. f

One object of the invention is the provision of a firearm having a bolt mechanism of improved construction and operation.

Another object of the invention is 'tov improve:

the action of the bolt mechanism of an automatic firearm.

A still further object of the invention is the provision of an automatic firearm having provision for retarding the return of the bolt toy breech-closing position after the bolt has been.

moved rearwardly'by the ring reaction.v

A still further and more specific object of the4 invention is the provision of a firearm having a bolt mechanism moved rearwardly in the receiver by the firing reaction and returned to breechclosing position by a spring, the firearm beingA provided with a detent to delay the return ofl cartridge from themagazine to the chamber, for

improving the striker and spring assembly which moves the striker forwardk when the trigger `is pulled, and which returns the bolt to forward'v position, and to improve other parts of the bolt action of a firearm whereby this action will be` positive and efficient and at the same time may be economically constructed.

' To these and other ends lthe invention consists in t-he novel features and combinations of partsL to be hereinafter described vandclaimed. In the accompanying drawings: Fig. 1 is avsectional View through the material portion of the mechanism of an automatic fire-- arm; Fig. 2 is a similar'view showing the parts in another position; Fig. Slis a view similar to Fig. 1 showing a modified form of my invention;

Figs. 4 and 5 are views similar to Fig. 3 but showing different positions of the parts; v Fig. 6 is an exploded view of the strikerand spring assembly shown in Fig; y1; j Fig. '7 is a detail elevational View of the throat member shown in Figs. 1 and 2; l y K.

Fig. Sisa partial sectional viewof a receiver arid bolt mechanism showing a modified form of bolt-retarding mechanism; and l Fig. 9 is a View similar .to Fig. 8,showing a further modification. To illustrate one embodiment of Ymy invention I have shown in Fig. 1 ofthe drawings an automatic firearm of the rifle type having a stock I0,

invention are the iin-` provement of the mechanism for transferring athe small opening I1 through which is lmoved the flringpin I8, the latter being secured onfthe end of a striker I9 reciprocably mounted in the bore.

IB of the bolt. This bolt isgalsoprovidedwith a longitudinally extending slot opening downwardly through the lower portion thereof, and within this slot rides a lug 2| on the striker provided with a shoulder portion 22 'designed to be engaged by the trigger sear, as will be hereinafter described. Y Y

Toward its forward' end the boltV isprovided with cut-out or recessed portions 23 and 24 between which isa cam member or surface 25 which serves to operate the cartridge-.lifting mechanism.

The receiver is open at its lower forward end, and communicates at thisfpoint with an upwardly facing opening in a Vthroat member 26, the forward part of which extends intorthe magazine II, as shown at 21, and is there secured. The throatllA is slotted longitudinally, and a lifter member` 28 is. pivoted to the receiver and is adapted to swing upwardly through this slot to raise a' cartridge from `the throat into position to be forced into the chamber in the barrel,

The lifter 28 is not only pivotally connected to the receiver, .but isV alsovallowed a limited bodily movement, in ,a vertical direction. To this end a pin 29 is secured to the lifter 28, and this pinV is movably mounted in slots 30 arrangedupon each side wall` of a lug 3I, this lug being slotted longitudinally Vtopermit the bodyportion of the lifter to pass therethrough. A spring 32 is provided below the member 28Vto normally maintain the pin in` raised position in'the slots30. The lifter 28 is also provided with a finger 32a to normally close thek throat-26 against the entrance thereinto of a shell from the magazine IIa when the lifter isV in raised position.

The lifter is also provided with projecting fingers 33 and 34, these lingers extending upwardly into the receiver to be engaged by the cam surface 25. It will be apparent 'that when the bolt is moved rearwardly from the position shown in Fig. 1,- the cam surface 25 will strike the finger 34-,an'd throw the forward end of the lifter `upwardly to force a cartridge from the throat into the receiver in position to be Vmoved into the chamber. At this time, however, it will not be possible to move thev cartridge upwardly to its ilnal position, and for this reason the pivot pin 29 of the lifter is permitted to move downwardly,

so that the finger-.34 maybe cammedvto its4 lowermost position bythe member 25, as shown in Fig. 2.l When the cartridge has beenjmove'd forward slightly by the bolt and is free to move intoY the receiver, the spring32 below the lifter moves the pinand the forward endof kthe lifter 28 upwardly,

which throws the cartridge into the receiver inV a position from which itis ready to move into the chamber.

' The striker I9 is threadedly secured tothe foropening in the sleeve being reduced at its forward end, however, as shown at 40, so that it will be retained upon the pin 31 at all times. As the striker is somewhat larger than the pin 31, a shoulder`4I is provided at the junction of these two parts, and between this shoulder and the forl ward end of the sleeve 39 is a compression spring 42 Vserving to urge the striker I9 forwardly to fire the gun. It may be here stated that the rear end of the sleeve 39 is supported by the bottom portion of the recess I5 in the cap I4.

Mounted upon the sleeve 39 and acting against the enlarged rear end 43 thereof is a second spring 44, which embraces the sleeve and also embraces the spring 42. At its forward end the springf44 is adapted to act against a shoulder 45 in the boreof the Vbolt I3, and this spring tends to maintain the bolt in the forward breech-closingV position shown in Fig. 1. The springs 42 and 44 will preferably be wound in opposite directions so that the outer one will slide freely over the inner spring. It will be apparent that with this construction the striker I9, pin 31, sleeve 39 and associated springs may be removed from the' bolt and will remainV as an assembled structure,V due to the fact that the sleeve cannot be forced from the pin 31 by the springs. These parts may be readily disassembled andreassembled by virtue of the threaded connection between the pin 31 and the striker I9.

Secured to the rearportion of the receiver is aslottedlug 50 between the parts of which is mounted a trigger 5I upon the pivot pin 52, the forwardend of the trigger being provided with a sear 53 to engage the shoulder 22 on the striker I9 to retain the gun in cocked position, and to effect its release ,when desired. The trigger extends rearwardly of the pivot pin 52, and a spring 54 acts between the receiver and the rear end of the trigger to normally force the latter forwardly and urgeV the sear into position to engage the shoulder' 2 2. v

`The rear portionV ofV the triggerrstructure is recessed, as shown at 55, and in this recess is slidably mounted a detent 56, the movement of the detent being limited by a pin 51 secured to the trigger, which pin is received in a slot 58 provided in the 'detent 56. A spring 59 normally urges the detent to an outward or protracted position. The outer end of the detent is beveled, as shown at 60, so thatthe detent may becammed downwardly into the recess 55 by the rear'end of the bolt I3 when the latter is movedto -the rear portion of the 'receiver during the operation of the'gun. Y

f A short distance forwardly of its rear end the bolt is provided with a notchr `lil within which the detent 56 is adapted to be engaged when the bolt has been thrown rearwardly, and when the trigger is in position to force the'detent 56 into th receiver, asV shown in Fig. 2.

It'will be' apparent that when the partsare in Y is moved upwardly against the spring 54, thus moving' the detent 56 toY a position within the receiver, as'shown in l;'ig.v2.Y When inj this position ofthe parts ktheboltis thrown rearwardly, the detent 56 will be cammed downwardly against most of its ylength to Vpass over the head 38, the

.. the action of the spring Y59 by the rear end of the bolt. `As soon, however,A as the notch 6I in the However, when the .triggerV is pulled, in order to effect release of the shoulder 22 by the sear 53. the rear portion 4of the triggerV bolt registers with the detent 56, the spring 59 will force the detent upwardly to engage the rear portion of the notch 6| and hold the bolt in retracted position, as shown in Fig. 2..

In this position of the parts, both of the springs 42 and 44 will be in compressed position, as the movement of the bolt will compress the outer spring against the shoulder 45, and as the striker is moved rearwardly with the bolt, the striker spring 42 will be compressed between the forward end of the sleeve 31 and the shoulder 4|.

As long as the trigger is held rearwardly by the finger in the position in which the firearm is discharged, the bolt will be prevented from being moved forwardly to breech-closing position. As soon, however, as the trigger is released by the finger, it will be returned to its original position by the action of the spring 54. This movement of the trigger will move the detent downwardly to release the bolt, due to the pin and slot connection between the detent and the trigger, and at the same time the sear 53 will be moved upwardly to engage the shoulder 22 on the striker. Thus, while the bolt will immediately be moved to breech-closing position by its spring when the trigger is released, the striker will be retained in cocked position by the engagement therewith of the sear 53. This retardation of the return movement of the bolt during the time that the trigger is engaged by the finger will permit ample time to elapse for the lifter 28 to move the cartridge in position to be thrown into the chamber by the forward movement of the bolt, and there will be no tendency for the parts to jam,

In Figs. 3 to 5 of the drawings I have shown a form of my invention applied to a vgun having Iring mechanism of slightly different construction. In this instance the barrel of the gun is shown at Il, the receiver at I2, and the mechanism for throwing the cartridge into the chamber from the magazine may be the same as that described in connection with the form of my invention shown in Figs. 1 and 2.

In this instance the bolt, instead of being a single member, is'divided into two portions, the front portion or bolt proper and the rear portion or hammer 15. The front portion is provided with a slot 11 substantially T-shaped in cross section, and within this slot is slidably` vided with a transversely extending head 8i at its rear end, which head seats in a circumferential slot 82 in the hammer t6, and it will be understood thatthe hammer is also longitudinally slotted, as at 83, to receive the body oi the striker 18.

The hammer 16 is hollow, the openingtherethrough being somewhat reduced at its forward end, as shown at 84, and extending through the hammer is a pin 85 provided with a head 86 against which is urged a washer 8'.' by a bolt spring 88 surrounding the pin 85 and reacting against a washer 89 secured at the opposite end of the pin and resting in the opening I5 of the cap I4, which closes the rear end of the receiver. v

Also Surrounding the pin 85 and embracing the spring 88 is a second spring 99 wound in the direction opposite to that of the first spring, which second spring also reacts against the head or washer 89 at one end and against the reduced portion 84 of the bore of the hammer 16 at the other end. It will be understood that the spring 88 tends to maintain the bolt in its forward position, as shown in Fig. 3, while the spring 90 tends to maintain the hammer in a forward position against the rear end ofthe bolt.

In Fig. 3 of the drawings the bolt is shown in its forward breech-closing position, but the hammer is in itsrear or cocked position, being held in this .position by the sear 9| of a trigger 92 pivoted at 93 to the lug 94 secured to the receiver, the trigger being urged by the spring 95 to a position in which the sear engages the hammer to hold the latter in its rear or cocked position. It will be understood that when the trigger is pulled,the sear 9| is moved downwardly, and the hammer 16 released. The hammer spring 90 then drives the hammer forwardly, and the hammer carries with it the striker 'I8 and firing pin 19, which strikes the shell in the chamber.

In order that the return of the bolt may also be delayed in this instance, after it has been thrown rearwardly by the ring reaction to permit sumcient time for the new cartridge to be moved into position to be thrown into the chamber, I have provided a detent to engage the bolt and hold it in rearward position until the trigger is released. This detent is shown atl 91, and is provided with a slot 98 which loosely receives a pin 99, the pin passing through the walls of a slotted lug lll secured to the receiver, through the slot of which the detent 91 extends. In order that the detent will be controlled by the action of the trigger, the forward portion of the latter is provided with a recess or socket IBI which slidably receives the rear end |02 of the detent. A compression spring |93, acting against the bottom of the recess, normally forces the detent outwardly or to the right with respect to the end of the trigger.

The lower portion of the bolt is provided with a notch or recess |04 within which is adapted to engage the pointedor hooked end |05 of the detent 91, when the latter is projected within the receiver through the opening |96, as shown in Fig. 4.

The operation of this form of my device will now be described. As the parts are shown in Fig. 8, the gun is cocked and ready to re. It will be noted that the bolt is also provided with a recess |01, which, when the bolt is in full breech-closing position, will lie directly above the end |05 of the detent 91. This permits the end of the detent to enter that slot when the trigger is pulled, and if the breech bolt were not in full closed position and the slot did not register with the detent, as shown, for example, in Fig. 5, it would not be possible to pull the trigger.

When the trigger is pulled the hammer is moved forwardly by its spring, and when the cartridge is discharged both hammer and bolt are moved rearwardly to the position shown in Fig. 4 by the firing reaction. As the forward end of .the trigger is pulled downwardly at this time, and

as the rear portion of the bolt cams the end of the detent downwardly and rearwardly during the rearward motion of the bolt, the detent must be permitted a certain amount of longitudinal movement upon the pivot pin 99, as it would not otherwise be permitted to rock downwardly with the trigger in the position shown in Fig. 5. The provision of the slot 98 allows this movement, as shown in Fig. 5, so that the detent member 91 can move downwardly and realv/ardly, and thus permit the bolt to pass. -As soon as the notch |04 in the bolt arrives oppositethe end |05 of the detent 91, the spring |03 moves the vdetent member 91 forwardly and upwardly, according to the movement permitted by the slot 98,y and effects engagement of the detent portion |05 in the slot |04 of the bolt, as shown, for example, in Fig. 4 of the drawings. The bolt is, therefore, held in a rearward position and will not be allowed to move forwardly by its spring until the trigger is released to move the'detent from engagement with the bolt. Upon release of the,V triggersthe forward end of the trigger is moved upwardly by the vspring 95, and the sear 9| is engaged in front of the hammer to holdv it in a rearward position at Vthe same time that the detent |05 is moved downwardly to permit the bolt'to be moved to forward position. This arrangement provides for the retarding of the forward movement of the bolt until ample time has been allowed to permit a new cartridge to Ybe thrownv into position to enter the chamber. l

' In Figs. 8 and 9 of the Vdrawings I have shown some modified forms of my invention with respect to the retarding of the return ofthe breech bolt. As shown in' Fig. 8,.the bolt |3, disposed in the receiver I2, is provided adjacent its rear end Y with a recess ||0 having a beveled end-surface Pivoted to Vthe receiver at ||2 is a detent 3 having a correspondinglyY beveled end ||4. The detent I3 is provided with a tail portion l5 against which acts a compression spring ||6 the other end of whichbearsagainst a portion of the receiver. v Y Y;

It will be apparent that the spring |6 will tend to maintain the detent in its upper position shown in Fig. 8, although it will permitthe detent to be cammed downwardly by the bolt upon its rearward movement. When the bolt reaches the position shown in Figg, the detent will be forced upwardly by the spring, and the beveled end |4 will engage the beveled surface of the recess H0, and kmomentarily retard the return of the bolt under action of the bolt spring.y It will be understood that the angles of the beveled surfaces and ||4 are not such 'that the bolt will be maintained in its rearward position by the detent, butlthe angles of these surfaces are only suiciently steep to momentarily retard the bolty and then permit it to slip by under the action of its spring, and bycamming the detent downwardly return to closed position. I have foundthat an angle of approximately"30 isrsuit-v able for this purpose.

In Fig. 9 of the drawingsy the bolt I3 is provided with aV recess |20 within which is disposed adetent |2| pivoted to the bolt at |22. A compression spring |23V normallymaintains the Ydetent in its lowerposition, where its beveled surface |24 will engage the beveled surface |25 at the end of a recess |26 formed in the wall'of the receiver.

In this instance when the bolt is thrown rear- Vunderstood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the appended claims.

Ysaid shoulder, a striker, and a second detent to control said striker, said second detent being actuated by the trigger. Y

2. A firearm comprising a receiver, a trigger, a breech bolt reciprocably mounted in the Vreceiver and adapted to be moved rearwardly by the firing reaction, a spring-to return saidbolt to its forward position, said bolt being provided Y with a shoulder, a detent member having an end portion adapted to engage Ysaid shoulder, said detent being connected to the receiver by a pin and slot connection, said trigger being provided with a recess, and the other end portion of Said detent member being received in said recess whereby said other end portion is moved relatively to the receiver by movement of the trigger, a striker, a second'detent controlling said striker, and said second detent being operatively connected to said trigger to be controlled thereby.

A firearm comprising a receiver, a trigger,

a breech bolt reciprocably mounted in the re-v ceiver and adapted to be moved rearwardly by Vportion adaptedfto-engage said shoulder, said detent being pivotally connected to the receiver by a pin and slot, connection, said trigger being providedfwith a recess, the vother end portion of said detentV memberrbeing received in said recess whereby said other end portion is moved Vrelatively to the receiver by movement of the trigger, and a spring in said recess tending to maintain said pin at one end of said slot, a striker, arseco'ndV detent controlling said striker,

and said second detent being operatively connected to the trigger to be actuated thereby.

4. A rearm comprising a receiver7 a breech bolt slidably mounted therein and Vdriven back by the recoil of the gun, said bolt having a forwardlydirected detent face, a spring to returnv said breech bolt to its forward position, a detent member pivotally connected to the receiverhaving a forward end portionVV adapted. to `engage said face when the rear end of said member is depressed, said pivotalconnection also permitting longitudinal movement of Vsaid member, -a trigger pivotallycarried by the receiver-and having an arm projecting forwardly of its pivot, the

rear end of said detent member being engaged by said arm whereby the former is depressed when the triggeris pulled, spring means urging said member forwardly with respect to its pivot,

a hammer disposed rearwardly of said breech bolt and carried rearwardly thereby, said hammer having a holding face, a cooking sear carried bolt Vslidablyinounted therein and driven back bythe recoilof the gun, said bolt having a for# wardly directed detent face, a spring to return said breech bolt to its forward position, a detent member pivotaliy connected to the receiver having a forward end portion adapted to engage said face when the rear end of said member is depressed, said pivotal connection also permitting longitudinal movement of said member, a trigger pivotally carried by the receiver and having an arm projecting forwardly of its pivot, a socket in the forward end of said arm, the rear end of said detent member being engaged in said socket TIMOTHY F. HORAN. 

